DonStegall

My Feedback: (1)

I've flown the LA Racer 40 and the Sky Raider Mach II throttled back and they fly fine at lower speeds.

But since some groups are using the OS .40 LA engine, I want to get first hand experience with the reduced power. Plus I may try to make it to one or more of the Florida Club 40 races this year. And since we are establishing two performance levels for [link=http://www.rcpro.org/html/rules/club_40/club_40.htm]RCPRO Club 40[/link], I feel that I really should know what I'm talking about when the topic of bushing engines comes up.

I had an white, black, and red LA Racer 40 that is partially assembled. The cowls for the current LA Racer 40 are pre-cut for the LA, and the engine mount is pre-drilled. Normally I re-drill new screw holes for the TT Pro 40 that are about a quarter inch back and tap them. But I decided to go ahead and make this plane Silver class ready with the OS 40 LA.

I got a couple of the engines a few weeks back. Today was pretty nice but a little too breezy and gusty to fly. So one of my projects for the day was breaking in the LA.

I put it on the test stand and mounted my break-in prop that I normally use on the ball bearing .40 engines. It is an APC carbon fiber 7.8x6 prop. I thought it might be too much of a load for the LA, but I fired it up with 15% Omega anyway. I keep a tach handy even when I first start up an engine, so I can set it by numbers. The engine was surprisingly tight. And apparently my flight box starter battery is getting a little weak. I even tried my geared starter I use for 4 strokes. I finally got it started after several tries.

After a couple of short runs, it would turn up to about 14,500 without pushing it too hard. I thought maybe I should try the APC 9x5 Sport Prop, and I got about 13,700 with it. I was surprised by the lower number. So I switched back to the CF prop. After about 5 tanks of fuel, it was turning up to 15,300. It was getting late so I didn't try the 9x5 again.

I was planning on using a 9x5 to fly with, but I thought I would ask what you guys are using on the Club 40 planes with the LA engines???

I've had good success with the 9x6 on the TT Pro 40 as long as I fly a smooth course. A 10x5 works better for tight turns on the TT. So I'm thinking of trying possibly even a 10x4 on the LA for shorter 2 pole courses to keep the rpms up.

Ken Erickson

Don,

The props we are using on the LA 40 for our 2-pole racing on a 400 foot course.

We in San Antonio, on our 400 foot course are using 10 X 6 APC or 11 X 4 APC. Not sure how they tach. We mostly go by what it does in the air.

The 11 X 4 would probably not be usefull at all at 600 feet. Might want a 9 X 6.

The Skyraider has a lot more drag than a Quickie.

Ken Erickson

dwbebens

Don & Ken;

In the spirit of sharing good information because Club 40 is supposed to be a fun and an entry-level event:

Don't even consider any 9" diameter props! I've tried just about every brand, diameter, and pitch and tested them in racing conditions. Believe it or not, the best prop I've found is the 10-7 APC. Actually, if you can find one, a 10.5-7 is even better. The OS 40 LA does NOT like to rev - - it's a lugger. The Mk II slows down a lot in the turns and you need to accellerate quickly out of the turn (prop diameter) and still have some pull left in the latter part of the straight-a-way ( prop pitch). I go off the line at about 10,800 RPM! The only problem that developes with these heavy props is the danger of needling too lean at the start.

Then again, we in Florida run a 600' two-pole course and we need the straight-a-way speed capability. If you were to run a 400' two-pole course, I would imagine that the prop requirements would be different; probably an 11-5.5 or 11-5 would be better.

Doug Bebensee

Ken Erickson

Doug, and everybody,

That's the spirit we hope we are going after!!!!!

Ken Erickson

DonStegall

My Feedback: (1)

Doug,

Thanks for sharing. I'll pick up some props in the sizes you recommended. For the time being I went ahead and put a 9x5 on it. But if a 10x6 or 10x7 works, by gosh I will try it.

This was the first time I have put an OS 40 LA in an LA Racer 40. With the TT Pro 40, you have to grind out the cowl and redrill the mounting holes. Actually I think you can get by without redrilling the holes, but it puts the cowl pretty far forward.

I did not have to trim the cowl at all. Just bolt the motor on, stick the cowl on, put the spinner backplate on, and tape the cowl in place. Drill the pilot holes and put the screws in. Very simple. You do have to take the needle valve out while you are putting the cowl on, and it is reasonably tight getting it on, but it goes just fine.

I have never liked The World Models pilots. I know the planes are produced in Asia, but I don't want an Asian pilot in my "American Piloted" plane. I have learned that you can simply repaint the face of the pilots and make them look like about whatever you want them to. I painted this one with model car acrylics. It actually looks a little feminine, but hey, I've never painted my face, and it just doesn't come natural. But it looks better (to me) than it did.

I used a 2 ounce Great Planes Spinner Weight and the balance was just fine with the JR Sport receiver and 700 mAh battery in the standard position.

Ken Erickson

Don,

You could put a mustache on him.

Ken

Jim Duda

No comment...

DonStegall

My Feedback: (1)

Jim,

Have you ever thought about writing songs?

I think that beard needs some gray in it. Maybe I'll do a Duda next. [sm=shades_smile.gif]

I flew the LA Racer 40 with the OS 40 LA today. Today started with medium winds but by the time I got to fly, it was gusting to 15.

I had the APC 9x5 on it and it flew faster than I thought it would. Even if it is a little faster with better prop selection, this is a good speed for pylon newcomers.

I didn't even fly the whole first flight. I handed the transmitter over to a new guy from Nebraska. He was very impressed with the stability in the wind. He has a couple of NIB OS LA's at home and he is ready to get an LA Racer 40 and start racing. These Club 40 planes sell themselves. If someone won't get one, they just aren't a candidate for racing. I tried to sell him on a Sky Raider Mach II, but he wants what he flew, even though it's a few more bucks.